Locking connector and floor treating machine utilizing same



Sept. 3, 1968 N. N. OKUN 3,400,361

LOCKING CONNECTOR AND FLOOR TREATING MACHINE UTILIZING SAME Filed Nov. 5, 1966 INVENTOR. NATHANIEL N. OKUN ayduMM ATTORNEYS United States Patent 3,400,361 LOCKING CONNECTOR AND FLOOR TREATING MACHINE UTILIZING SAME Nathaniel N. Okun, Baltimore, Md., assignor to The Cello Chemical Company, Baltimore, Md., a corporation of Maryland Filed Nov. 3, 1966, Ser. No. 591,756 10 Claims. (Cl. 339-75) ABSTRACT OF THE DISCLOSURE A separable electrical connector comprises a male body made of yieldable insulating material and having two spaced collateral metal prongs projecting therefrom, a female body made of yieldable insulating material and having two spaced collateral passages to receive the prongs with the bodies in end-to-end relation, said passages having metal contacts therein to engage the prongs for electrical connection. There is a releasable means to hold the said two bodies against separation, said means including a hook shaped member having a handle part and a large round :hook passing through a transverse hole in the male body and releasably received in another transverse hole in the female body, said [hook having a diameter approxlmately the same as the spacing between said two holes but the parts are stressed for resilient frictional engagement. The hook member and the holes are located in said bodies in the region between the two spaced collateral prongs and passages.

This invention relates to separable electrical connectors, especially locking connectors, and more particularly to such a connector suited for use between the handle and motor of a floor treating machine.

The general object of the present invention is to improve separable electrical connectors of the locking type. A more particular object is to provide a simplified and inexpensive locking means for such a connector.

Floor treating machines commonly employ a handle which is pivotally and detachably secured to the motorized body of the machine. A long flexible electrical supply cable is connected to the handle with its control switch, and a short flexible loop of cable is provided between the handle and the motor. It is convenient to make the handle detachable from the body, and in such case the flexible loop of cable must be provided with a separable connector. The continuous flexing of the cable during operation of the machine, and also when storing the machine at which time the handle is turned upright, tends to loosen the connector with consequent arcing at and damage to the contacts.

A further object of the present invention is to provide a detachable connector which is particularly suited for use in a floor treating machine for the described purpose.

To accomplish the foregoing general objects, and other more specific objects which will hereinafter appear, my invention resides in the locking connector elements and their relation one to another, as are hereinafter more particularly described in the following specification. The specification is accompanied by a drawing in which:

FIG. 1 is a perspective view showing a floor treating machine embodying the improved separable connector;

FIG. 2 is a partially sectioned elevation showing the connector in locked condition;

FIG. 3 is a similar view showing its locking member swung to released position;

FIG. 4 is an elevation drawn to smaller scale and showing the parts of the connector separated;

FIG. 5 is an end view of the female body of the connector; and

FIG. 6 is a view taken on the line 6-6 of FIG. 2.

Patented Sept. 3, 1968 ice Referring to the drawing, and more particularly to FIG. 1, I there show a floor treating machine having a motorized body 12, a handle 14 which is pivotally and detachably secured to the body 12, and along flexible electrical supply cable 16 which is connected to the upper end portion 18 of the handle. The present machine is of the large industrial type, and its operation is controlled by switch mechanism housed in the body 18, and operated by either of two levers 20 disposed near the transverse grip portions 22 of the handle 14. The switch is connected by a cable which usually is run through the tubular handle 14, and which emerges at a short flexible loop 24 which leads to the motor 26. Because it is convenient to make the handle 14 detachable, the loop 24 includes a separable electrical connector generally designated 30.

This tends to loosen because of the continual oscillation of the handle when the machine is in use, and any loosening of the plug leads to arcing inside the plug, thus greatly shortening the useful life of the same. To avoid this, I have devised an improved plug with a simple and inexpensive locking means to guard against loosening or sepa ration.

Referring now to FIGS. 2 through 6 of the drawing, the separable electrical connector there shown comprises a male body 32 made of insulating material, and having two spaced collateral prongs 34 (FIGS. 4 and 6) projecting therefrom. There is a generally similar female body 36 made of insulating material and having two spaced collateral passages 38 (FIG. 5) to receive the prongs 34, with the bodies 32 and 36 in end-to-end relation. The passages 38 have metal contacts 40 therein to engage the prongs 34 for electrical connection.

The releasable means to hold the bodies against separation comprises a hook shaped member 42 mounted in one body and releasably received in a mating hole 44 in the other body, the said member 42 and hole 44 being located in the space between the spaced collateral prongs 34 and passages 38. The member 42 is preferably located in the male body 32, so that on separation the female body 36 is unencumbered, as shown in FIG. 4, it being understood that in usual practice the female body is the live body, electrically.

In preferred form the bodies 32 and 36 are made of an insulating material which is somewhat yieldable or rubber-like, and indeed they may be made of rubber. This provides for resilient engagement with the hook shaped member 42, the proportioning of the parts being such that there is a maintained pressure when the hook is engaged.

As here shown the male body 32 has a transverse hole 46, much like the hole 44 in the female body, and the hook portion 42 has a handle 48 projecting therefrom. This handle when swung to a position over the female body as shown in FIG. .3, moves the hook 42 to released position, and when swung to a position over the male body 32 as shown in FIG. 2, moves the hook 42 to locking position.

From examination of the drawing it will be seen that both the male and female bodies are longitudinally recessed at the top and bottom, as shown at 50. This substantially reduces the height of the body between the spaced collateral prongs and passages, and the transverse holes 44 and 46 terminate in the recesses 50.

The hook shaped member 42 is rigid and made of steel wire. The wire may be twelve gauge steel wire of the type and hardness used for example in ordinary clothes hangers. Such wire is commonly available, and therefore the hook may be made inexpensively. The addition of the locking device to the connector consequently adds very little to the expense of the connector.

The hole 44 is initially straight, as shown in FIG. 3. The hole 46 similarly is initially straight.

The distortion of the rubber around the hole 46, caused by the curvature of the hook 42, helps hold the hook against escape when in the released position shown in FIGS. 3 and 4. Similarly, referring to FIG. 2, the rubber around the hole 44 is distorted by the curvature of the hook, and the simultaneous distortion of the rubber at both holes helps hold the hook in locked position shown in FIG. 2. In addition, there is friction caused by the compression of the material between the holes 44 and 46 when the spacing is slightly reduced in order to help assure tight locking together of the two parts of the connector.

It is believed that the construction and method of use of my improved separable electrical connector, as well as the advantages thereof, will be apparent from the foregoing detailed description. It also will be apparent that while I have shown and described the connector in a preferred form, changes may be made without departing from the scope of the invention, as sought to be defined in the following claims.

I claim:

1. A separable electrical connector comprising a male body made of insulating material and having two spaced collateral metal prongs projecting therefrom, a female body made of insulating material and having two spaced collateral passages to receive the prongs with the bodies in end-to-end relation, said passages having metal contacts therein to engage the prongs for electrical connection. and releasable means to hold the said two bodies against separation, said means including a hook shaped member having a handle part and a large round hook passing through a transverse holes in one body and releasably received in another transverse hole in the other body, said hook having a diameter approximately the same as the spacing between said two holes, said member and said holes being located in said bodies in the region between the two spaced collateral prongs and passages.

2. A separable electrical connector as defined in claim 1, in which the handle is an extension of the hook shaped member, and in which the said handle is so directed that when swung to a position over one body serves to move the free end of the hook out of the hole in that body to released position, and when swung to a position over the second body serves to move the free end of the hook into the hole in the first body to locking position.

3. A separable electrical connector as defined in claim 1, in which the male and female bodies are both longitudinally recessed at the top and bottom and thereby reduced in height in the region between the spaced collateral prongs and passages, and in which the transverse holes for the hook shaped member are located in the re cessed parts of the bodies.

4. A separable electrical connector as defined in claim 1, in which the holes are so spaced and dimensioned relative to the hook as to stress the parts when connected, and in which the insulating material of the two bodies is a yieldable rubber-like material which provides a resilient engagement with the hook shaped member when received in the mating hole.

5. A separable electrical connector as defined in claim 4, in which the holes are straight, and are deformed by the curvature of the hook shaped member, to provide a frictional engagement.

6. A separable electrical connector as defined in claim 1, in which the part of said hook nearer the handle part of said member passes through and remains in the hole in the male body, whereby the member is mounted on and carried by the male body when the two bodies are separated.

7. A separable electrical connector as defined in claim 6, in which the holes are so spaced and dimensioned relative to the hook as to stress the parts when connected, and in which the insulating material of the two bodies is a yieldable rubber-like material which provides a resilient engagement with the hook shaped member when received in the mating hole in the female body.

8. A separable electrical connector as defined in claim 7, in which the handle is an extension of the hook shaped member and in which the handle is so directed that when swung to a position over the female body serves to move the free end of the book out of the hole in the female body to released position, and when swung to a position over the male body serves to move the free end of the hook into the hole in the female body to locking position.

9. A separable electrical connector as defined in claim 8, in which the male and female bodies are both longitudinally recessed at the top and bottom and thereby reduced in height in the region between the spaced collateral prongs and passages, and in which the transverse holes for the hook shaped member are located in the recessed parts of the bodies.

10. A separable electrical connector as defined in claim 9, in which the holes are straight, and are deformed by the curvature of the hook shaped member, to provide a frictional engagement.

References Cited UNITED STATES PATENTS 283,502 8/1883 Mathes 292l 664,144 12/1900 Gerhart 339-91 1,169,486 1/1916 Holmes 287ll9 3,179,738 4/1965 De Lyon 339--91 MARVIN A. CHAMPION, Primary Examiner.

JOSEPH MCGLYNN, Assistant Examiner. 

